Related
Updated and simplified version here : http://forum.xda-developers.com/showthread.php?p=3846897#post3846897
I've been around this forum for some time now and I have noticed one thing that is spelled in all sub-forums: BATTERY LIFE
So I thought of pulling some info together that is relevant to our Raphs (Li-ion batteries), taken from www.batteryuniversity.com.
Hope you find it helpful and understand better behaviour of your battery
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About the Author
Isidor Buchmann is the founder and CEO of Cadex Electronics Inc., in Vancouver BC.
Mr. Buchmann has a background in radio communications and has studied the behavior of rechargeable batteries in practical, everyday applications for two decades. Award winning author of many articles and books on batteries, Mr. Buchmann has delivered technical papers around the world.
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"If possible, do not discharge lithium-based batteries too deeply. Instead, recharge more often."
Lithium-ion is a low maintenance battery, an advantage that most other chemistries cannot claim. There is no memory and no scheduled cycling is required to prolong the battery's life. In addition, the self-discharge is less than half compared to nickel-cadmium, making lithium-ion well suited for modern fuel gauge applications.
Lithium-ion has not yet fully matured and is being improved continuously. New metal and chemical combinations are being tried every six months to increase energy density and prolong service life. The improvements in longevity after each change will not be known for a few years.
Charging
There is only one way to charge lithium-based batteries. The so-called 'miracle chargers', which claim to restore and prolong batteries, do not exist for lithium chemistries. Neither does super-fast charging apply. Manufacturers of lithium-ion cells have very strict guidelines in charge procedures and the pack should be charged as per the manufacturers "typical" charge technique.
Lithium-ion is a very clean system and does not need priming as nickel-based batteries do. The 1st charge is no different to the 5th or the 50th charge. Stickers instructing to charge the battery for 8 hours or more for the first time may be a leftover from the nickel battery days.
Most cells are charged to 4.20 volts with a tolerance of +/?0.05V/cell. Charging only to 4.10V reduced the capacity by 10% but provides a longer service life. Newer cell are capable of delivering a good cycle count with a charge to 4.20 volts per cell.
A lithium-ion battery provides 300-500 discharge/charge cycles. The battery prefers a partial rather than a full discharge. Frequent full discharges should be avoided when possible. Instead, charge the battery more often or use a larger battery. There is no concern of memory when applying unscheduled charges.
Batteries live longer if treated in a gentle manner. High charge voltages, excessive charge rate and extreme load conditions have a negative effect on battery life. The longevity is often a direct result of the environmental stresses applied. The following guidelines suggest ways to prolong battery life.
The time at which the battery stays at 4.20/cell should be as short as possible. Prolonged high voltage promotes corrosion, especially at elevated temperatures. Spinel is less sensitive to high voltage.
The lower charge current reduces the time in which the cell resides at 4.20V. A 0.5C charge only adds marginally to the charge time over 1C because the topping charge will be shorter. A high current charge tends to push the voltage into voltage limit prematurely.
Do not discharge lithium-ion too deeply. Instead, charge it frequently. Lithium-ion does not have memory problems like nickel-cadmium batteries. No deep discharges are needed for conditioning.
Do not charge lithium-ion at or below freezing temperature. Although accepting charge, an irreversible plating of metallic lithium will occur that compromises the safety of the pack.
Not only does a lithium-ion battery live longer with a slower charge rate; moderate discharge rates also helps.
Discharge of the lithium-ion battery is 5% in the first 24 hours after charge, and then reduces to 1% to 2% per month thereafter. The safety circuit adds about 3%. High cycle count and aging have little effect on the self-discharge of lithium-based batteries.
The battery industry is making incremental capacity gains of 8-10% per year. This trend is expected to continue. This, however, is a far cry from Moore's Law that specifies a doubling of transistors on a chip every 18 to 24 months. Translating this increase to a battery would mean a doubling of capacity every two years. Instead of two years, lithium-ion has doubled its energy capacity in 10 years.
Although lithium-ion is memory-free in terms of performance deterioration, batteries with fuel gauges exhibit what engineers refer to as "digital memory". Here is the reason: Short discharges with subsequent recharges do not provide the periodic calibration needed to synchronize the fuel gauge with the battery's state-of-charge. A deliberate full discharge and recharge every 30 charges corrects this problem. Letting the battery run down to the cut-off point in the equipment will do this. If ignored, the fuel gauge will become increasingly less accurate.
Despite its overall advantages, lithium-ion has its drawbacks. It is fragile and requires a protection circuit to maintain safe operation. Built into each pack, the protection circuit limits the peak voltage of each cell during charge and prevents the cell voltage from dropping too low on discharge. In addition, the cell temperature is monitored to prevent temperature extremes. The maximum charge and discharge current on most packs are is limited to between 1C and 2C. With these precautions in place, the possibility of metallic lithium plating occurring due to overcharge is virtually eliminated.
The worst condition is keeping a fully charged battery at elevated temperatures, which is the case with running laptop batteries. If used on main power, the battery inside a laptop will only last for 12-18 months. I must hasten to explain that the pack does not die suddenly but begins with reduced run-times.
The voltage level to which the cells are charged also plays an important role to longevity. For safety reasons, most lithium-ion cannot exceed 4.20 volts per cell. While a higher voltage boosts capacity, the disadvantage is lower cycle life.
"how deep can a battery be discharged and still achieve maximum service life?" There are no definite answers. Batteries are like us humans. Suppose we ate all the vegetables our mother heaped on our plates and do our daily exercise, would we life longer? Perhaps. But by how much, no one will know. Batteries lose capacity as part of aging, cycling and exposure to heat. Nickel-cadmium also loses capacity due to lack of exercise because of memory.
Some lithium-ion batteries fail due to excessive low discharge. If discharged below 2.5 volts per cell, the internal safety circuit opens and the battery appears dead.
Aging is a concern with most lithium-ion batteries and many manufacturers remain silent about this issue. Some capacity deterioration is noticeable after one year, whether the battery is in use or not.
Lithium-ion batteries lose capacity through cell oxidation, a process that occurs naturally during use and aging. The typical life span of lithium-ion is 2-3 years under normal use. Cool storage a 40% charge minimizes aging. An aged lithium-ion cannot be restored with cycling.
Shorted Cells
Cell reversal caused by deep discharging also contributes to shorted cells.Specified to deliver 100% capacity when new, the battery should be replaced when the capacity drops to below 80% of the nominal rating.
The self-discharge on all battery chemistries increase at higher temperatures. Typically, the rate doubles with every 10°C (18°F). A noticeable energy loss occurs if a battery is left in a hot vehicle.
Premature voltage cut-off
Not all stored battery power can be fully utilized. Some equipment cuts off before the designated end-of-discharge voltage is reached and precious battery energy remains unused. Applications demanding high current bursts push the battery voltage to an early cut-off. This is especially visible on batteries with elevated internal resistance. The voltage recovers when the load is removed and the battery appears normal. Discharging such a battery on a moderate load with a battery analyzer to the respective end-of-discharge threshold will sometimes produce residual capacity readings of 30% and higher.
Counterfeit cell phone batteries (clone batteries)
In the search for low-cost battery replacements, consumers may inadvertently purchase clone cell phone batteries that do not include an approved protection circuit. Lithium-ion packs require a protection circuit to shut off the power source if the charger malfunctions and keep on charging, or if the pack is put under undue stress (electrical short). Overheating and 'venting with flame' can be the result of such strain.
Cell phone manufacturers strongly advise customers to replace the battery with an approved brand. Failing to do so may void the warranty. Counterfeit cell phone batteries have become visible since the beginning of 2003 when the world was being flooded with cheap replacement batteries from Asia.
Cell phone manufacturers act out of genuine concern for safety rather than using scare tactics to persuade customers to buy their own accessories. They do not object to third party suppliers in offering batteries and chargers as long as the products are well built, safe and functioning. The buyer can often not distinguish between an original and a counterfeit battery because the label may appear bona fide.
Caution should also be exercised in purchasing counterfeit chargers. Some units do not terminate the battery correctly and rely on the battery's internal protection circuit to cut off the power when fully charged. Precise full-charge termination and a working protection circuit are needed for the safe use of the lithium-ion battery.
A large number of lithium-ion batteries for cell phones are being discarded under the warranty return policy. Some failed batteries are sent to service centers or the manufacturer, where they are refurbished. Studies show that 80%-90% of the returned batteries can be repaired and returned to service.
© Copyright 2003 - 2005 Isidor Buchmann
Great thread! Wiki!
Thanks
Tis is good info to know and to share. Thanks for putting this together for us all.
overcharging Fuze battery
When I exchanged my Fuze for a new one at AT&T, the service person said my battery was bad, due to overcharging. She said leaving my Fuze plugged into my car charger and my computer(with charging turned on) degraded the battery.
There is an option to NOT charge the battery when connected by USB to the computer.(kind of indicates no automatic charging control)
Well, I use my Fuze as a computer 12-14 hours a day. I want to see the screen, which means I need it plugged in either to the computer or car charger.
If I turn off recharging when connected to my computer, I end up with a dead battery pretty quickly, since I use it a lot as my business phone with a Bluetooth speakerphone.
The AT&T person said this information was given to them by HTC.
Thank you for the infos. Really need this cause battery life is my main concern.
recharge cycles
from reading other posts, it looks like the batteries have around 1000 recharge cycles.
Unfortunately, the cycles can occur every time you plug into your computer or charger, even if the charge goes from 99 to 100 %.
Which means I need a new battery probably every 9-12 months. Not too bad.
hrothnir said:
When I exchanged my Fuze for a new one at AT&T, the service person said my battery was bad, due to overcharging. She said leaving my Fuze plugged into my car charger and my computer(with charging turned on) degraded the battery.
There is an option to NOT charge the battery when connected by USB to the computer.(kind of indicates no automatic charging control)
Well, I use my Fuze as a computer 12-14 hours a day. I want to see the screen, which means I need it plugged in either to the computer or car charger.
If I turn off recharging when connected to my computer, I end up with a dead battery pretty quickly, since I use it a lot as my business phone with a Bluetooth speakerphone.
The AT&T person said this information was given to them by HTC.
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Which tells you how much you should listen to most AT&T people about technical issues and details. They were 100% wrong about the impact of charging continuously. And unless they were talking to an HTC hardware engineer...
It's more likely that your issues were simply caused by heavy use, which will cause any rechargeable battery to wear out more quickly. Most batteries I've seen will last between 500-1000 charging cycles, so if you're a heavy user and are wearing down your battery frequently, you'll "run through" those charging cycles more quickly.
The advice you were given is worth ignoring.
does it make any difference
Does it make any difference if i charge my fuze from a
- charger connected to power outlet
or
- an USB cable connected to compute
Obviously, the USB option takes longer time to charge completely.
I wanted to know, which is suggested?
hrothnir said:
from reading other posts, it looks like the batteries have around 1000 recharge cycles.
Unfortunately, the cycles can occur every time you plug into your computer or charger, even if the charge goes from 99 to 100 %.
Which means I need a new battery probably every 9-12 months. Not too bad.
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Charging from 99-100% definitely will not qualify as "One" cycle. Discharging from 100% to some 20% and then charging up may count as one cycle. Similarly, 5 or 6 shallow discharging and charging 60%-40%-60% can count as one cycle. It is much better for battery health though. charging momentarily for one or two minutes which increases the battery percentage by 2-3% will not count as a full cycle.
Here is some information that should be useful to everyone in one way or another if not then you should have told us your secret months ago. lol
A Li-ion batteries life is on a time clock from the day it's produced and how it is used, maintained and the number of cycles it goes through reduces it's life. Even when not being used at all the clock is ticking and life is shortening.
So if any of you are like me I know many of you are far worse than me when it comes to the amount of stress put through it with flashing and extreme general use. Hopefully this will shed some light for us as to what we can do to try and prolong the life of our batteries.
The majority of the following information is from the book “Batteries in a Portable World – A Handbook on Rechargeable Batteries for Non-Engineers” (2nd edition) and Battery University™
Special thanks to the books author and sponsor of Battery University™,
Isidor Buchmann
CEO and Founder, Cadex Electronics Inc.
How to Prolong the Life of Li-ion Batteries
Battery wear-down on lithium-based batteries is caused by two activities: actual usage or cycling, and aging. The wear-down effects by usage and aging apply to all batteries but this is more pronounced on lithium-based systems.
The Li-ion batteries prefer a shallow discharge. Partial discharges produce less wear than a full discharge and the capacity loss per cycle is reduced. A periodic full discharge is not required because the lithium-based battery has no memory. A full cycle constitutes a discharge to 3V/cell. When specifying the number of cycles a lithium-based battery can endure, manufacturers commonly use an 80 percent depth of discharge. This method resembles a reasonably accurate field simulation. It also achieves a higher cycle count than doing full discharges.
Simple Guidelines
Charge the Li-ion often, except before a long storage. Avoid repeated deep discharges.
Keep the Li-ion battery cool. Prevent storage in a hot car. Never freeze a battery.
Avoid purchasing spare Li-ion batteries for later use. Observe manufacturing date when purchasing. Do not buy old stock, even if sold at clearance prices.
Hints to long battery life
3.92V/cell is the best upper voltage threshold for cobalt-based lithium-ion. Charging batteries to this voltage level has been shown to double cycle life. Lithium-ion systems for defense applications make use of the lower voltage threshold. The negative is reduced capacity.
The charge current of Li-ion should be moderate (0.5C for cobalt-based lithium-ion).The lower charge current reduces the time in which the cell resides at 4.20V. It should be noted that a 0.5C charge only adds marginally to the charge time over 1C because the topping charge will be shorter. A high current charge tends to push the voltage up and forces it into the voltage limit prematurely.
Memory Myth or Fact?
Lithium batteries are not affected by memory, but the chemistry has its own peculiarities. Current inhibiting pacifier layers affect them through plate oxidation. This degenerative effect is non-correctable on a lithium-based system
Calibration
A more serious issue is maintenance requirements, better known as capacity re-learning. This procedure is needed on a regular basis to calibrate the battery.
Why is calibration needed?
The answer is in correcting the tracking errors that occur between the battery and the digital sensing circuit during use. The most ideal battery use, as far as fuel-gauge accuracy is concerned, is a full charge followed by a full discharge at a constant 1C rate. This ensures that the tracking error is less than one percent per cycle. However, a battery may be discharged for only a few minutes at a time and commonly at a lower C-rate than 1C. Worst of all, the load may be uneven and vary drastically. Eventually, the true capacity of the battery no longer synchronizes with the fuel gauge and "a full charge and discharge are needed to ‘re-learn’ or calibrate the battery."
How often is calibration needed?
The answer lies in the type of battery application. For practical purposes, a calibration is recommended once every three months or after every 40 short cycles.
What happens if the battery is not calibrated regularly? Can such a battery be used in confidence?
Such a battery is able to function normally, but the digital readout will be inaccurate. If not corrected, the fuel gauge information simply becomes a nuisance.
Just Tell Me WTF I Should Do!
Charge your battery as often as possible, partial discharges are actually better for your battery
Once your battery is charged to 100% avoid leaving it plugged in any longer if you are not using a OEM charger.
Your battery should never get hot from charging if it does this is a sign it may be damaged.
If fuel gauge starts acting up calibrate your battery.
Yeah but how the f^$% do I calibrate my battery?
Charge phone up and then delete your battery stats.
Unplug your phone from your wall charger and let your battery drain all the way down until phone shuts off.
While still off charge phone to 100% and then boot up as normal.
There is so much more that it's mind boggling but I think this covers the main parts and beyond for everyone. So far it appears that the bump method is not necessary nor are the numerous other steps.
I can only laugh when I think that the reason the method of calibration I was using was actually working is due to the fact that the "wipe batt stats, drain battery completely and charge to 100%" is basically the last step and all that is essentially needed.
3 hours? That's it? I thought whenever I charged from empty to full when it's off it's longer.. I should time it.. hmm
darkamikaze said:
3 hours? That's it? I thought whenever I charged from empty to full when it's off it's longer.. I should time it.. hmm
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I removed the time completely since some may vary. But the 3 hours is how long it should take to charge on a standalone battery charger. So rather than confuse or have questions it's better without it.
Nice work!
Charging a 1500mAh battery at 500mAh for example will take 3 hours. The Captivate charges at 2 levels though depending on if it's USB (500mAh max for charge + phone use) or a charger (whatever it says on the charger up to ~1200mAh) so it can probably get done in under 2 hours.
The phone charges to 4.23V and stops charging when full but continues to run on external power, and shuts down at 3.500V where it only consumes current to monitor the power button.
Just for reference.
Battery Stats
Since this is the first time i had a really good battery life. I would like to share it with everyone. Please see the attached screen shots.
I am using Darky's 9.1 with SuckerPunch's 1280/500 Kernel and TLJL3 modem.
I hope this will help anyone trying to get more battery life out of their Captivate.
Thanks,
CuriousTech said:
Nice work!
Charging a 1500mAh battery at 500mAh for example will take 3 hours. The Captivate charges at 2 levels though depending on if it's USB (500mAh max for charge + phone use) or a charger (whatever it says on the charger up to ~1200mAh) so it can probably get done in under 2 hours.
The phone charges to 4.23V and stops charging when full but continues to run on external power, and shuts down at 3.500V where it only consumes current to monitor the power button.
Just for reference.
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Click to collapse
Thanks Curious appreciate it and thanks for the additional info.
I had some other random thoughts about the calibration because I keep seeing so many posts daily.
For example "I installed a new kernel 15 minutes ago, recalibrated and the battery drain is horrible." or "After a few charges it lasted longer."
I don't think people get the idea of calibration. Recalibrating determines the capacity of the battery to convert to a % full gauge. To do that you need to fully charge until the "Battery full. Unplug charger." notification, and not rely on the display and unplugging as soon as it hits 100%. That's the inaccurate display that you're trying to calibrate.
Think of it like having an opaque container and a teaspoon. You think the container can hold 100 teaspoons, so you stop filling at 100. All you can get out of it is 100 until you try to fill until it tops off and then count how many come back out.
The phone works the same way. It has an ammeter that monitors the charge current and drain current from the battery from the time you unplug it until it shuts off and remembers that total as the capacity. Unless it's recharged in the middle which voids the data.
After that full discharge, it should stay pretty accurate even with partial discharges. At least until the next rom/kernel flash which wipes it out. At that point (I assume) it uses a simple voltage level and some relative amps drawn to display the gauge, instead of the smarter method of keeping a constant value of mAh by adding when charging and subtracting when draining to know exaclty how full the battery is.
CuriousTech said:
Nice work!
Charging a 1500mAh battery at 500mAh for example will take 3 hours. The Captivate charges at 2 levels though depending on if it's USB (500mAh max for charge + phone use) or a charger (whatever it says on the charger up to ~1200mAh) so it can probably get done in under 2 hours.
The phone charges to 4.23V and stops charging when full but continues to run on external power, and shuts down at 3.500V where it only consumes current to monitor the power button.
Just for reference.
Click to expand...
Click to collapse
hm. so if the phone switches to external power when the charge is full, is it okay to leave my phone plugged in once it's done charging? or is it just the fact that the battery is holding a full (4.2V) charge for a long time that's bad for its health?
in any case, useful post! i knew there were ways to preserve the life of li-ion batteries, but was never well-versed on the details.
Yes to both. Once the battery is fully charged, the charge circuit stops completely. It doesn't even need to trickle charge, so leaving it plugged in doesn't hurt anything.
Once the charge is complete the voltage isn't being held at 4.20V so it can come back down a little. I think BatteryUniversity generalizes becuase there have been many different designs over the years that weren't as good as what we have now, and some may have trickle charged their Li-Ions which shortens the life.
Which is it that wipes the battery stats, ROM or kernel? or is it both?
CuriousTech said:
Yes to both. Once the battery is fully charged, the charge circuit stops completely. It doesn't even need to trickle charge, so leaving it plugged in doesn't hurt anything.
Once the charge is complete the voltage isn't being held at 4.20V so it can come back down a little. I think BatteryUniversity generalizes becuase there have been many different designs over the years that weren't as good as what we have now, and some may have trickle charged their Li-Ions which shortens the life.
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One word of caution though is to ensure that you are using an OEM charger. Battery University recommends that you unplug once capacity is reached but perhaps this is a general statement for Li-ion batteries as you state.
zerkai said:
Which is it that wipes the battery stats, ROM or kernel? or is it both?
Click to expand...
Click to collapse
Both. The first thing in a ROM flash script is to format all the partitions, so that means the batterstats.bin file is erased. When flashing a new kernel the file gets reset by some other means. No idea what. It could be CWM.
Yeah but how the f^$% do I calibrate my battery?
Charge phone up and then delete your battery stats.
Unplug your phone from your wall charger and let your battery drain all the way down until phone shuts off.
While still off charge phone to 100% and then boot up as normal.
My noob question is, how do you delete the battery stats?
iNFRiNGE said:
One word of caution though is to ensure that you are using an OEM charger. Battery University recommends that you unplug once capacity is reached but perhaps this is a general statement for Li-ion batteries as you state.
Click to expand...
Click to collapse
What happens when you introduce the variable of occasional car charger use?
Sanctus Peregrinus said:
Yeah but how the f^$% do I calibrate my battery?
Charge phone up and then delete your battery stats.
Unplug your phone from your wall charger and let your battery drain all the way down until phone shuts off.
While still off charge phone to 100% and then boot up as normal.
My noob question is, how do you delete the battery stats?
Click to expand...
Click to collapse
the file is located at /data/system/batterystats.bin . you'll need a file browser with root access (i use root explorer, a paid app). make sure you mount the storage as read/write or you won't be able to delete the file.
after that, reboot your phone and it will rebuild the batterystats file.
***disclaimer: be careful doing this. if you delete a crucial file, you risk messing up or bricking your phone. such is life.
Nice write up with alot of interesting information. I have never calibrated my battery but will have to try it out. Thanks for posting.
Sent from my SAMSUNG-SGH-I897 using XDA App
I'm not positive of this, but I don't think batterystats.bin holds any battery capacity or health info. I was looking at BatteryManager and it looks like a database of processes and what they use only. But there is info somewhere that gets lost easily, which is the capacity and current amount consumed.
I've been skipping the delete of that file (using CWM) and have noticed that it recalibrates fine anyway. This coming from the point of dropping just after unplugging, which is a good indication that the info is gone.
It doesn't matter if you use a car charger, USB, or AC. The phone has the actual smart charger in it, the external connection is just the power supply. The chip inside regulates and monitors the charge.
So think of it this way. The charger knows when the battery is empty or full, and measures what goes in and comes out. So to know the capacity, it has to go from full to empty. That's really all there is to it. Just wait for the real "Battery full" before unplugging.
Just ordered a dock for my S3 and was planning to use it at work, so the phone would be plugged into a charger 8hrs \ weekday. Will this kill my battery?
ubernewf said:
Just ordered a dock for my S3 and was planning to use it at work, so the phone would be plugged into a charger 8hrs \ weekday. Will this kill my battery?
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No. That doesn't affect LION batteries. have done it for years with tablets and other LION batteries.
ubernewf said:
Just ordered a dock for my S3 and was planning to use it at work, so the phone would be plugged into a charger 8hrs \ weekday. Will this kill my battery?
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No, lithium ion batteries have no battery memory like nickel cadmium ones. Charge whenever and as long as you want!
I let my phones, and my other Li-ion battery appliances charge everyday all night long. I can't imagine it being much different then charging while you're at work. Worst case scenario is your battery starts to not hold its charge a year from now, and then you could just get a new battery before the 1 year warranty is over.
I thought that while there is no memory effect with Li-ion batteries, they do die quickest when at maximum and minimum charge, and last longest when at 40-50% charge.
Per Wikipedia:
A Standard (Cobalt) Li-ion cell that is full most of the time at 25 °C (77 °F) irreversibly loses approximately 20% capacity per year. Poor ventilation may increase temperatures, further shortening battery life. Loss rates vary by temperature: 6% loss at 0 °C (32 °F), 20% at 25 °C (77 °F), and 35% at 40 °C (104 °F). When stored at 40%–60% charge level, the capacity loss is reduced to 2%, 4%, and 15%, respectively.[50] In contrast, the calendar life of LiFePO4 cells is not affected by being kept at a high state of charge.[51]
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Avoid deep discharge and instead charge more often between uses, the smaller the depth of discharge, the longer the battery will last.[106][unreliable source?]
Avoid storing the battery in full discharged state. As the battery will self-discharge over time, its voltage will gradually lower, and when it is depleted below the low-voltage threshold (2.4 to 2.9 V/cell, depending on chemistry) it cannot be charged anymore because the protection circuit (a type of electronic fuse) disables it.[106][unreliable source?]
Lithium-ion batteries should be kept cool; they may be stored in a refrigerator.[106][unreliable source?][107]
The rate of degradation of Lithium-ion batteries is strongly temperature-dependent; they degrade much faster if stored or used at higher temperatures.[106][unreliable source?][108]
The rate of degradation of Lithium-ion batteries is also related to battery charge level; they degrade much faster when at 100% charge, than at lower charges. Since batteries die if deep discharged (depleted) and since a battery has some self-discharge it is frequently recommended to store batteries at 40% charge level.[109]
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I'm not sure exactly which kind of Li-ion battery they are using as it seem some types are more immune to this effect than others.
But yeah, while it's not going to instantly kill your battery, it will cause it to lose capacity over time. This is the same reason why you shouldn't leave your laptop battery plugged in all the time.
I appreciate what you're doing there but I think it's hard to quote something as fact when it says "unreliable source" "unreliable source" "unreliable source" "unreliable source"...
Ha yeah I saw that but whatever. Wikipedia was just the first place I checked, I'm almost positive I've seen the same basic information elsewhere. And anecdotally I know I've laptop batteries stop holding charge after just a year or two when left plugged in 24/7.
This is also the reason that cell phones don't keep the battery charged at 100% when it's left plugged in. It goes to 100%, lets the battery die down to 90%ish, then charges back up to 100%, etc. It's trying to avoid keep the battery at 100%.
I read that a battery will last longer if you don't let it get below 40%, and full discharges are bad for the longevity. Is this true? Here is a good read on the subject. http://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries
Jspeer said:
I read that a battery will last longer if you don't let it get below 40%, and full discharges are bad for the longevity. Is this true? Here is a good read on the subject. http://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries
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Click to collapse
that is true. the affect is probably minimal though(like we probably lose .7% of our battery per month if dont let it get low before charging it, instead of the typical 1% per month)
i get through half of my day with about 50% battery less, sometimes more. so i've made it a habit of charging it once i see it's around this 50% mark.
Jspeer said:
I read that a battery will last longer if you don't let it get below 40%, and full discharges are bad for the longevity. Is this true? Here is a good read on the subject. http://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries
Click to expand...
Click to collapse
The effect is accelerated/more pronounced below 20%...
Here is the good thing though... These phone's minimum operating voltage is higher than the minimum voltage of a Li ION battery. Using standard battery life measurements, the 0% according to the phone, is about 20% of standard.
Should you do a full discharge every now and then in order to calibrate the battery? I haven't been able to find a definitive answer on this in other related threads. Some say you should, some say it's not necessary since the battery doesn't have memory cells. I have never let my battery get below 50% and everything seems to work fine but it does seem to make sense to do a full discharge from time to time so the battery knows its capacity.
Jspeer said:
Should you do a full discharge every now and then in order to calibrate the battery? I haven't been able to find a definitive answer on this in other related threads. Some say you should, some say it's not necessary since the battery doesn't have memory cells. I have never let my battery get below 50% and everything seems to work fine but it does seem to make sense to do a full discharge from time to time so the battery knows its capacity.
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Li-ON battery's do not need to be calibrated. that was only with old battery tech such as Ni-Cad or NIMH
I let mine get low all the time I use my phone a lot. Hopefully its not to expensive to replace battery since Google thinks that replacing a battery is to complicated for us tech savvy people
Justice for Kelly Thomas RIP
I don't worry about it. I charge it overnight. If I've over used it in the day and I feel it will die before bed, i'll top it up but not to protect the battery. Just to ensure I can use my phone.
If they wanted you to do anything special with charging / draining, it would be in the instructions
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markdapimp said:
Li-ON battery's do not need to be calibrated. that was only with old battery tech such as Ni-Cad or NIMH
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The battery itself does not but occasionally the controller needs a kick in the pants. Deep drains on li-ion should be avoided at all costs. The phone hasn't been out long enough to even think about the sort of problem. But after a couple hundred charges you might see a behavior that will be corrected by one full discharge.
Its not uncommon to see cases where you actually replace the cell behind a controller and the controller not picking up the change in capacity. Never in cell phones mostly laptop battery rebuilds etc but it exhibits an idea of what happens. The battery controller takes note of the original, current maximum and current charge capacity. Not sure how I suppose voltage versus read amp hours. But as a battery gets old you might start seeing the maximum capacity reading fluctuate. But if at any time the actual chemical capacity is higher than the controller thinks it is the controller will prevent the battery from reaching its potential.
Used to have older PSP batteries reach 100% real quick, quick fix was to deep discharge through the controller using a small light bulb. The battery would then take a significant charge and last a few more months before kicking the bucket.
Jspeer said:
I read that a battery will last longer if you don't let it get below 40%, and full discharges are bad for the longevity. Is this true? Here is a good read on the subject. http://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries
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40% is a good number for storage, its actually better to store it at 40% than 100%. Actual use 20 to 25% is my personal range but I would say just never let it get below 15%. Lithium Ion does not mind being topped off. Deep discharged will ruin it real quick. My laptop battery lasted 3 years never letting it go below 25%, murdered a cell phone battery once a year letting it die.
I let it go to 1% and turn itself off. Then I charge it back up. But if I know I am going out in the next few hours I charge it as much as I can before I leave.
markdapimp said:
Li-ON battery's do not need to be calibrated. that was only with old battery tech such as Ni-Cad or NIMH
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lots of the fuel gauges for these types of batteries do need to be calibrated. this is not true for the N5 though(i think). I want to say i remember reading that this fuel gauge is different, like a 'smart fuel gauge' or something
kmx said:
I let it go to 1% and turn itself off. Then I charge it back up. But if I know I am going out in the next few hours I charge it as much as I can before I leave.
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You shouldn't do that almost ever. And by no means as a regular practice.
Molitro said:
You shouldn't do that almost ever. And by no means as a regular practice.
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Thats what the built in protection is for:
Marine6680 said:
The effect is accelerated/more pronounced below 20%...
Here is the good thing though... These phone's minimum operating voltage is higher than the minimum voltage of a Li ION battery. Using standard battery life measurements, the 0% according to the phone, is about 20% of standard.
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Enddo said:
lots of the fuel gauges for these types of batteries do need to be calibrated. this is not true for the N5 though(i think). I want to say i remember reading that this fuel gauge is different, like a 'smart fuel gauge' or something
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Click to collapse
Its not any different. as with older battery technologies they would loose capacity until they are calibrated 0% to 100% this is due to the chemistry of the battery
LI-ON battery's have a different chemistry which allows them to store greater capacity without loss like NI-CAD and NIMH did this is why you turn off your phone for a week and turn it on you find it still has about the same battery percentage as you turned it off before.
here's an example of a NI-CAD battery which needs to be calibrated.
You have a drill you haven't used for 3 days it was fully charged before you put it away if you take that same drill 3 days later you'd find it dead. where as LI-ON battery's would still be alive and full capacity. if you charge it from there it wouldn't be calibrated. as calibration requires you to drain the battery 2 times or more till it reaches it full capacity and charge it back up to 100% and repeat.
If you were to do that with a LI-ON battery you're basically doing nothing but wasting your charge cycles on the battery and you could kill it as LI-ON battery's DO NOT LIKE TO BE EMPTY
Because of all that NI-CAD and NIMH mess mostly all power tools you'd find in a shop such as home depot are now equipped with LI-ON battery's as they don't require calibration and can be left for months and it would still have its initial capacity prior to charging because Ni-cad battery's suffer from a memory effect and LI-ON does not, NI-CAD Requires full discharge before recharge LI-ON does not you get the point here right? LI-ON is better!
Now for those apps that claim calibrate the battery they do nothing they just Improve the reading of the software in android to get the battery percentage which is reset every time the battery charges to 100% so in short don't calibrate your battery
You can read more here http://www.diffen.com/difference/Li-ion_vs_NiCad
and watch this video: http://www.youtube.com/watch?v=hrcbcm11830
markdapimp said:
Its not any different. as with older battery technologies they would loose capacity until they are calibrated 0% to 100% this is due to the chemistry of the battery
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The battery controller is still the source of the problem. If the batteries chemical capacity at a given moment is 1800 mah down from its original 2300 and the charge controller thinks the capacity is 500 the controller will only charge the battery to 500. Most controllers do not act like their dumber counter parts which will trickle or cut off when the cells characteristics indicate it is reaching a full charge.
The controller in these batteries while varying greatly in design all have one thing in common. They are designed for safety. The controller will actually stop accepting a charge forever if the voltage of the cell goes below a certain point. It will also never charge it above the current observed maximum capacity no matter what reality is.
You can poll a battery using vendor specific commands to get the designed, current maximum and current charge. The current maximum charge capacity is a changing value it will change over the life of the battery. This was an aging laptop battery that while the controller knew what the "Full Charge Capacity" was currently it decided not to report that to windows resulting in a hilarious 410%.
But we are talking about a problem that really won't rear its head for 1 or 2 years and were talking about doing it once or twice over the life of the battery. People doing it now and all the time WILL kill the battery very quickly for no benefit.
markdapimp said:
Its not any different. as with older battery technologies they would loose capacity until they are calibrated 0% to 100% this is due to the chemistry of the battery
LI-ON battery's have a different chemistry which allows them to store greater capacity without loss like NI-CAD and NIMH did this is why you turn off your phone for a week and turn it on you find it still has about the same battery percentage as you turned it off before.
here's an example of a NI-CAD battery which needs to be calibrated.
You have a drill you haven't used for 3 days it was fully charged before you put it away if you take that same drill 3 days later you'd find it dead. where as LI-ON battery's would still be alive and full capacity. if you charge it from there it wouldn't be calibrated. as calibration requires you to drain the battery 2 times or more till it reaches it full capacity and charge it back up to 100% and repeat.
If you were to do that with a LI-ON battery you're basically doing nothing but wasting your charge cycles on the battery and you could kill it as LI-ON battery's DO NOT LIKE TO BE EMPTY
Because of all that NI-CAD and NIMH mess mostly all power tools you'd find in a shop such as home depot are now equipped with LI-ON battery's as they don't require calibration and can be left for months and it would still have its initial capacity prior to charging because Ni-cad battery's suffer from a memory effect and LI-ON does not, NI-CAD Requires full discharge before recharge LI-ON does not you get the point here right? LI-ON is better!
Now for those apps that claim calibrate the battery they do nothing they just Improve the reading of the software in android to get the battery percentage which is reset every time the battery charges to 100% so in short don't calibrate your battery
You can read more here http://www.diffen.com/difference/Li-ion_vs_NiCad
and watch this video: http://www.youtube.com/watch?v=hrcbcm11830
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Click to collapse
look man
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
Partial discharge on Li-ion is fine; there is no memory and the battery does not need periodic full discharge cycles to prolong life, other than to calibrate the fuel gauge on a smart battery once in a while.
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Click to collapse
now believe what you want
Once in a while isn't explicit. The video posted earlier says once a year or so... both of those are "a while" to me
It all depends on the controller and the software but mostly its no longer necessary.
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Molitro said:
You shouldn't do that almost ever. And by no means as a regular practice.
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Thanks for the recommendation.:angel:
rootSU said:
Thats what the built in protection is for:
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Fair enough.
But still doens't seem like a good practice given how the recommendations with this kind of tecnology are usually don't go too low and try to charge at different values, not always plug the charger at the same level.
Li Ion batteries charge to a maximum voltage before the charge stops in a phone or other device that charges while also operating.
To fully charge a Li Ion battery you need to monitor current draw of the battery as it is charging, it drops as the cell reaches saturation. This is difficult to do in an operating circuit... Though the tech may be getting better, as load sharing was not common for charging cell phones a few years ago, but it may now be, I have actually been looking for info on powered device charging, but find little beyond load sharing type.
So the battery in a phone could hold more juice if it was charged out of the device, and more still if the phones could run at the 3v minimum of Li Ion. (min voltage of arm devices is around 3.5v) Load sharing chargers can charge fully though.
Also charge rate affects battery life... slower charging is better for long lifespan. If you overnight charge, use the lowest rated charger you have, or standard USB charging. The current phones come with higher amp chargers now... It really doesn't speed up the overall charge cycle to 100% very much, but it does make charging to 80% quicker. So you can do a quick charge of a low battery to a usable level in a hurry.
Power tools use LiFe chemistry batteries which are more tolerant of abuse and misuse... at the cost of less voltage and capacity and more weight.
I work from home so it's easy for me to top off the phone as needed. I'll usually throw it on the charger for a while around 3-ish PM to make sure that I have a full charge going into the evening since I do a lot of reading on it after the kids are in bed. I'm definitely what you would call an opportunistic charger - there's no need to drain the battery all the way unless you absolutely can't get to a charger. I don't understand why people choose to run their batteries down all the way when they don't have to.
A Li-ion battery has a limited numer of charge cycles, but what constitutes a charge cycle? According to some people a charge cycle is used every time the charger is connected. Another opinion is that only a charge from 0 - 100% consumes one charge cycle. So how is it really? If the first assumption is true then one should only charge when the battery is almost emty. If the other one is true then it's ok to charge at any time.
Tom200 said:
A Li-ion battery has a limited numer of charge cycles, but what constitutes a charge cycle? According to some people a charge cycle is used every time the charger is connected. Another opinion is that only a charge from 0 - 100% consumes one charge cycle. So how is it really? If the first assumption is true then one should only charge when the battery is almost emty. If the other one is true then it's ok to charge at any time.
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A charge cycle is the process of charging a rechargeable battery and discharging it as required into a load. The term is typically used to specify a battery's expected life, as the number of charge cycles affects life more than the mere passage of time. Discharging the battery fully before recharging may be called "deep discharge"; partially discharging then recharging may be called "shallow discharge.
Apple Inc. clarifies that a charge cycle means using all the battery's capacity, but not necessarily by full charge and discharge; e.g., using half the charge of a fully charged battery, charging it, and then using the same amount of charge again count as a single charge cycle. -Wikipedia
Hit thanks if I helped
Rumple007 said:
A charge cycle is the process of charging a rechargeable battery and discharging it as required into a load. The term is typically used to specify a battery's expected life, as the number of charge cycles affects life more than the mere passage of time. Discharging the battery fully before recharging may be called "deep discharge"; partially discharging then recharging may be called "shallow discharge.
Apple Inc. clarifies that a charge cycle means using all the battery's capacity, but not necessarily by full charge and discharge; e.g., using half the charge of a fully charged battery, charging it, and then using the same amount of charge again count as a single charge cycle. -Wikipedia
Hit thanks if I helped
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Ok, but that means that charging the battery a lot instead of waiting until it's almost completely drained, shortens its lifespan.
Ideally, a Lithium based battery is "healthiest" at or about mid level. A full charge cycle is technically not 0-100%, as these batteries (at least in consumer electronics) have circuitry built-in to prevent overcharging, overdischarging, and shorts. Overdischarging can cause what's called runaway discharge, where it'll keep discharging even if not connected to anything or the device is turned off. Heat, possible fire, and even explosion. Those Dell and Sony laptops that were catching fire several years ago? That was because the protection circuitry was faulty. And why you should always buy OEM factory batteries, or ones made by reputable companies like Zerolemon or Anker, and not cheap Chinese knockoffs. Hobbiests (flashlights, R/C equipment) often use unprotected batteries since they can get a bit more capacity out of them, but this is dangerous and requires monitoring and judgement.
So the answer is a charge cycle is from 0-100% and back down to 0% (or the opposite; charged, discharged, then charged - depending on your point of view), where 0% is the point where the circuitry within the battery and/or the device itself cuts the power.
There is no need to "condition" lithium rechargeable batteries (ie: fully drain them, don't use until fully charged, etc); this is a holdover from the days of nickel-cadmium (Ni-Cad) batteries, which did require conditioning for optimal performance.
The main destroyer of a lithium battery really isn't even the charge/discharging of it, but rather the heat associated with it. For example, one can keep a battery charging and charged at 95-100% while playing an intense game, downloading a large file, or running a wi-fi hotspot, but this sill quickly destroy the battery, even there's no actual "cycle" happening. The ~500 charge cycle figure assumes a typical usage of training and charging. The reason a battery is "healthiest" at mid levels is that this is where there's the least heat being generated.
Yeah, I have kind of adapted to the thought that charging whenever doesn't impact the battery in a negative way. So if my charge is 80% and I'm going out for the day, I still charge it to full 100%. If however (as the first answer suggests) this consumes an extra cycle then it would be best not to charge it. In the past this didn't matter so much but with many phones these days it's hard or even impossible for the user to replace the battery. This makes the answer to my question more important...
Tom200 said:
Yeah, I have kind of adapted to the thought that charging whenever doesn't impact the battery in a negative way. So if my charge is 80% and I'm going out for the day, I still charge it to full 100%. If however (as the first answer suggests) this consumes an extra cycle then it would be best not to charge it. In the past this didn't matter so much but with many phones these days it's hard or even impossible for the user to replace the battery. This makes the answer to my question more important...
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80-100% is not a cycle, it's 20% of a cycle. However, it is the worst part of the cycle (higher voltages, more heat). Ideally, for the battery's health and longevity over the months/years, it'd be best to keep it between, say, 30-70%. But this is impractical, potentially impossible for some, and, frankly, dangerous.
That's why I'll only buy phones with replaceable batteries. Either instantly, or without terrible difficulty when the battery hits that ~500 cycle mark. I have 3 phones: A Galaxy S4 (with a couple spares, including a 7800mAh Anker), a Nexus 4, which I've replaced the battery on, and a OnePlus One, which I know I can replace if/when I need to. I'll never get something like a S6 or Note5 or iPhone where battery replacement is nigh-impossible.
Planterz said:
80-100% is not a cycle, it's 20% of a cycle. However, it is the worst part of the cycle (higher voltages, more heat). Ideally, for the battery's health and longevity over the months/years, it'd be best to keep it between, say, 30-70%. But this is impractical, potentially impossible for some, and, frankly, dangerous.
That's why I'll only buy phones with replaceable batteries. Either instantly, or without terrible difficulty when the battery hits that ~500 cycle mark. I have 3 phones: A Galaxy S4 (with a couple spares, including a 7800mAh Anker), a Nexus 4, which I've replaced the battery on, and a OnePlus One, which I know I can replace if/when I need to. I'll never get something like a S6 or Note5 or iPhone where battery replacement is nigh-impossible.
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Yeah, it's very annoying that not batteries on all cell phones are user replaceable. And we can exchange them on some phones anyway with a little trouble, but as you write it's completely impossible with some. I put in the charge if my battery is 50% or something and I'm going out later. This should consume only half a a cycle and it's practical for me.
I now charge when the battery is like 75% before I'm going out. Is this ok or should I let the battery drain and then charge? The latter I did for a long time with a phone I had, and the battery had great performance until I sold it.